Patent GB-537406-A (GB)
Title: Improvements in or relating to apparatus for indicating the registration of a web ina multi-unit web conditioning apparatus, such as a multi-unit web printing press
IPC: B41F33/02
Filed: 1939-11-09
Abstract: 537,406. Photo-electric apparatus for indicating and correcting alignment of webs; valve relays. CHAMBON CORPORATION. Nov. 9, 1939, No. 29756. Convention date, Nov. 17, 1938. [Classes 40 (iii) and 40 (v)] [Also in Group XXXV] An apparatus for indicating the registration of a web in a multi-unit web-conditioning apparatus such as a printing press comprises a pair of photoelectric devices with a circuit operating an indicating arrangement, and an electromagnetic timing relay arrangement operated by electron discharge devices for controlling the actuation of the indicating arrangement. As shown, a web 10, Fig. 1, is fed through a multi-colour printing press 14, 16, 18, each unit comprising an engraved printing cylinder 28 cooperating with a resilient impression cylinder, and a wheel 32 with gearing for example as described in Specification 497,942 for adjusting the phase of the printing roller. A mark 48 on the wheel 32 is observed by a photo-electric device 46 comprising a lamp 78, Fig. 2, with a lens 80, and a photo-electric cell associated with a lens 82, a mirror 84, and a slot 86. Marks made on the web by the first printing unit 14 are observed by a similar photo-electric device. These photo-electric devices are adjustable on squared rods 52 which are themselves adjustable longitudinally by means of an end screw. Comparison is made between the times of operation of the photo-electric devices by thermionic valve circuits which cause a red lamp 92 to light up if the mark 48 on the wheel 32 is in advance of the mark on the web, or a green lamp 94 to light up if the mark 48 is behind, both lamps being out when the marks are in synchronization. In the circuit, Fig. 4, an impulse caused in the cell 90 by a mark 66 on the web 10 is amplified and fed to a gas-filled discharge tube 108 connected to a relay 122 which causes a green lamp 94 to light up. At the same time the plate current of tube 108 charges a condenser 138 in the grid circuit of a vacuum tube 140 connected to a timing relay 148 which after a given time cuts off the plate circuit of the discharge tube 108, whereupon the vacuum tube 140 goes out of action and the timing relay again closes the plate circuit of the discharge tube 108. Similarly, an impulse caused in the cell 88 by the mark 48 on the wheel 32 operates a relay 180 which lights up a red lamp 92. The discharge tubes 108, 172 are interconnected as shown so that the operation of one prevents subsequent action of the other for a given time. But, if both discharge tubes operate substantially simultaneously, both relays operate and the lamps remain unlit. A similar circuit, Fig. 4a (not shown), includes means for further facilitating initial adjustments and for limiting the amplitude of the pulses impressed on the grids of the discharge tubes. The Specification as open to inspection under Sect. 91, describes also a circuit which in addition to giving indications of registration also produces automatic correction of the web conditioning apparatus. This subject-matter does not appear in the Specification as accepted.